Structural abnormalities of the Y chromosome: Genotype-phenotype correlation

The aim of this study was to correlate the structural abnormalities of the Y chromosome to its presenting clinical features to evaluate the phenotype-genotype correlation. The study was performed on 30 patients who had structural Y chromosome abnormalities. The cytogenetic methods included conventional G-banding, diamidino-2-phenylindole [DAPI] and fluorescent in situ hybridization [FISH] techniques. The structural abnormalities of the Y chromosome were a deletion of the long arm [Yq-] in 13 cases, a partial deletion of the short arm [Yp-] in 6 cases, large heterochromatin of Y [Yq+] in 6 cases, pericentric inversion in 4 cases and one case with ring Y. Their phenotypic presentations varied from complete normal male, ambiguous genitalia to complete female phenotype. The clinical presentations and cause of referral of the patients were variable including male infertility and azoospermia, primary amenorrhea, mental retardation, multiple congenital anomalies and/or dysmorphism, short stature, ambiguous genitalia, routine premarital counseling and repeated abortions

Assessment of genome damage in a population of Egyptian workers occupationally exposed to cotton dusts

Earlier reports described byssinosis syndrome among workers in cotton industry, while recent studies have shown that workers occupationally exposed to cotton dusts have an increased risk of development of many types of cancer. Hence this study was conducted to assess genotoxic effects [as a measure of carcinogenic risk] of chronic cotton dust inhalation in workers with byssinosis and to combine clinical and occupational data with the results of genotoxicity assays in order to reach quantitativness in risk assessment. Clinically, byssinosis was diagnosed mainly in workers employed at early production areas of yarn preparation: opening, blowing and carding [80%] and those working as machine operators [8.5%]. There was significant correlation between the duration of exposure to cotton dusts and the clinical severity of the disease. Study of cytogenetic markers in exposed workers showed significant increase in the percent of total chromosomal breaks and aberrations as well as the mean value of sister chromatid exchanges accompanied with significant decrease in mitotic index value as compared to controls. Assessment of total genomic damage of DNA by visual comparing of the density of released [migrated, damaged] DNA bands and by measuring the optical density of damaged DNA bands using Gel-Pro computer program revealed 20% increase in DNA damage in blood lymphocytes of workers chronically exposed to cotton dusts when compared to non-exposed controls. Also, there was 50% increase in the optical density of the released RNA in blood lymphocytes of exposed workers than controls which might be used as an index of stress of pollution applied on cotton industry workers. Comet assay endpoints revealed more than twice times higher number of migrated DNA spots [damaged, strongly damaged] in blood lymphocytes from cotton industry workers compared to non-exposed subjects. The genotoxicity burden measured as% of total chromosomal breaks, and aberrations, mean values of SCEs/metaphase and DNA damage endpoints [the number of damaged DNA spots and the optical density of damaged DNA] was correlated significantly with the duration of exposure to cotton dusts. Therefore the fact that workers occupationally exposed to cotton dusts have distinctly more chromosomal mutations and DNA damage may be an important indicator in the chronic effect of cotton dust-associated carcinogenesis. Combining the clinical and occupational data with the results of genotoxicity assays showed that the severity of byssinosis syndrome was associated with the degree of genome damage

Monitoring of diesel exhaust exposed workers at risk by clinical and cytogenetic studies

Clinical assessment revealed that exposure to diesel exhaust [DE] inducedallergic manifestation with significant increase in the number of exposedworkers with clinical asthma, allergic conjunctivitis and eczema. Additionally, there was a significant increase in the percent of exposedworkers with auditory troubles and hypertension. Cytogenetic study revealedsignificant increase in the frequencies of chromosome aberrations [CA] andsister chromatid exchanges [SCEs] among exposed workers. Whereas, the mitoticindex insignificantly decreased. The increased duration of exposure to DEsignificantly affected the frequency of SCEs but not that of CA. Moreover,treatment of the cultures with N-acetylcysteine significantly decreased thefrequencies of CA and improvement of the mitotic index as compared withnon-treated cultures, whereas, no significant decrease was observed in thefrequencies of SCEs